Soaking pit cover with protected sealing means



Jan. 30, 1951 R. w. HIGGINS 2,539,421

SOAKING PIT COVER WITH PROTECTED SEALING MEANS Filed Nov. 25, 1946 4 Shee'ts-Sheet 1 Jan. 30, 1951 R. w. HIGGINS SOAKING PIT COVER WITH PROTECTED SEALING MEANS 7 4 Sheets-Sheet 2 Filed NOV. 25, 1946 WNW "F inn" hnnnnul ul n l Jan. 30; 1951 R. w. HIGGINS SOAKING PIT COVER WITH PROTECTED SEALING MEANS 4 Sheets-Sheet 3 Filed Nov. 25, 1946 II II Jan. 30, 1951 R. w. HIGGINS 2,539,421

SOAKING PIT COVER WITH PROTECTED SEALING MEANS Filed Nov. 25, 1946 4 Sheets-Sheet 4 j gw Patented Jan. 30, 1951 SOAKING PIT COVER WITH PROTECTED SEALING MEANS Robert W. Higgins, Evanston, 111., assignor to M. H. Detrick Company, Chicago, 111., a corporation of Delaware Application November 25, 1946, Serial No. 712,148

6 Claims.

The present invention relates to covers for soaking pits.

A soaking pit is one of a series of heating furnaces used in the steel industry for preparing products for rolling and shaping operations. Normally they constitute large, brick-lined chambers placed below the level of a charging floor. The top of the pit is left entirely open and is closed by a brick-lined removable cover, known as a soaking pit cover. It is this type of cover that forms the subject matter of the present invention.

The soaking pit is adapted to hold a plurality of steel ingots varying in number from about four to sixteen or more, depending upon the size of the pit and the ingots. Often a plurality of pits are disposed side by side, each pit being provided with its own separate cover.

During the period of operation of a pit of this type, temperatures of from 2200 F. to 2500 F. or more may exist in the pit and ingots may be charged into or removed from the pit while exceedingly high temperatures exist. The cover must be removed from the soaking pit durin this charging or discharging operation and to accomplish this the cover is often raised vertically above the pit and moved laterally to one side.

Normally a cover of this sort is lined on its inner face with brick of the type that can stand extremely high temperatures. During the period when the cover is being removed or applied to a soaking pit the lower peripheral edge of the cover, as well as the outer face along the sides of the cover are subjected to high temperatures and the corrosive effect of hot gases that escape from the soaking pit. Heretofore these hot gases and exposures to high temperatures have caused the rim of the soakin pit cover to burn and break away, thereby requiring a very large amount of maintenance in the way of replacements in order to keep the covers in operative condition.

' It is necessary for efficient operation of a soaking pit for the cover to provide a relatively effective seal so as to reduce to a minimum the escape of hot gases from the pit during the soaking period. This is accomplished by providing a sealing edge around the peripheral margin of the cover that becomes somewhat imbedded in a body of the cover subjected to the high temperatures and hot ases. This life is extended while at the same time the effectiveness of the seal is maintained.

During normal operation of a soaking pit it is often desirable to maintain a pressure in the pit greater than atmospheric. Thus there may be some hot gases escaping through the seal between the soaking pit cover and the body of silica sand that surrounds the pit, and these hot gases constantly passing across unprotected surfaces on the soaking pit cover. Where a plurality of soaking pits are disposed side by side the hot gases escaping from one soaking pit often subject the adjacent cover to the damaging effects of the high temperatures. The present invention is also intended to overcome this difficulty.

Thus the invention provides a soaking pit cover that can withstand extremely high temperatures, both during normal operation of the soaking pit to which it is applied and during the periods when the cover is being removed or applied to the pit. The life of the present soaking pit cover is substantially greater than that of previous covers and the maintenance problem is reduced to a minimum. This is all accomplished in a relatively simple manner at low costs.

The foregoing constitute some of the principal objects of the present invention, others of which will become apparent from the following description and the drawings, in which Fig. l is a vertical sectional view through a soaking pit and a soakin pit cover, portions of the cover being shown in elevation and the soaking pit being illustrated more or less diagramsilica sand that is disposed completely around the 1 and illustrating a seal casting applied to the cover;

Fig. 5 is a top plan view of one of the seal castings illustrated in previous figures;

Fig. 6 is a front elevational view of the casting shown in Fig. 5; v

Fig. 7 is an end elevational view of the casting shown in Fig. 6; g

Fig. 8 is a more or less diagrammatic bottom plan view of one corner only of a soaking pit cover embodying the present invention;

Fig. 9 is a view corresponding to Fig. 4 but illustrating a modified embodiment of the invention;

Fig. 10 is a horizontal sectional View through a portion of the cover, the view being taken on the line I i-50 of Fig. 9; and

Fig. 11 is a view corresponding more or less with Fig. 9 but illustrating still another embodiment of the invention.

For purposes of illustration certain embodiments of the invention have been selected, it being recognized, however, that many modifications may be made in the specific embodiments shown without departing from the intended scope of the invention.

Referring to Fig. l of the drawings the invention is illustrated in conjunction with a soaking pit generally indicated at 2B. -The soaking pit, per se, forms no part of the present invention, and is illustratedonly for the purpose of showing the relationship between the cover and a pit upon which it may be used. As shown in Fig. 1 the soaking pit 2i] comprises generally a pit 25 formed by vertical walls 22 that are arranged in the form of a rectangle. As shown the pit 2| is rectangular in shape and is provided with a bottom wall 23 that has an aperture 24 projecting upwardly therefrom. Apertures 25 are provided in at least certain of the side walls 22 and these apertures 25 lead to discharge chambers generally indicated at 2 A gas burner or the like 2? is provided adjacent to the lower end of the aperture 2E and is adapted to heat gases that are forced upwardly through the aperture 24 and into the pit 2i as indicated. These gases are caused to pass through the pit 2i and exhaust through apertures or ports 25 into the chambers 26 and finally leave the furnace through ducts 28 after passing over numerous baffles and the like.

The soaking pit 2! is adapted to contain a plurality of ingots 25} that are arranged in the pit as illustrated in Fig. l for example, in the path of the hot gases that are circulated through the pit. I

The soakingpit cover forming the subject matter of the invention is illustrated generally at 3li. This cover as best shown in Figs. 2 and 3 is rectangular in shape and comprises a pair of parallel, spaced I-beams 3i forming sides of the cover and I-beams 32 forming end walls of the cover. Intermediate spaced channel members 33 and spaced I-beams 3 form longitudinal and transverse reenforcing members that are rigidly secured to the side and end walls 38 and 32 respectively. Additional diagonal braces 35 are provided to further reeniorce the structure of the cover.

As shown in Fig. 3 a heat resisting wall generally indicated at 36 is suspended from the cover structure and comprises generally a plurality of firebricks 3i suitably suspended from certain of the I-beams by means of hangers 38. As indicated in Figs. 2 and 3 these firebricks 3! are of various sizes and shapes and protect the entire inner faces of the structural members of the cover from the intense heat that exists in the soaking pit chamber 2i.

Projecting downwardly from the I-beams 32 and 3i is an annular seal member generally indicated at 39 in Fig. 3 that comprises a channel member at (Figs. 3 and 4) that may be bolted or otherwise secured as at 4! to the lower flange of I-beams S2 or 3| as the case may be and a plurality of sealing units or castings 42. Each units 52 as shown at 54 (Fig. 8).

of the castings 42 comprises a substantially horizontal upper flange 43 having a web 44 pro-- jecting downwardly therefrom as best indicated in Figs. 5 to 7 inclusive. The casting 42 is generally rectangular in elevation as illustrated in Fig. 6 and is provided with a plurality of reeniorcing ribs 45 that extend from the upper flange 3 to a position adjacent to the bottom of the web Gfi. At the lower end of the web 4 is provided a sealing edge member 48 that extends for the full length of the sealing unit 42 and in cross section is substantially in the form of an isosceles trapezoid. The sealing edge 46 projects beyond both faces of the web 44 so as to provide an inner and outer shoulder portion 4i and 48 respectively. A plurality of lugs 49 project from the inner and outer faces of the web 44 and are spaced throughout the length of the unit 42. A plurality of slots 58 (Fig. 5) are provided in the upper flange .3 to each of the sealing units 42 and the units A2 are arranged in end to end relationship along the sides and ends of the cover, suspended by means of bolts 5| from the lower flange of the channel members 49. The bolts 5| pass through the slots 52? in the upper flange Q3 of each of the sealing units 42 and the sealing units may be applied by merely hooking the unit in place on the bolts 5|.

As best shown in Fig. 8 the sealing units 52 are spaced slightly apart so as to provide a slight space therebetween indicated at 52. As shown each face of the web 44 of each unit 42 is disposed inwardly with respect to the outermost edges of the castings (Fig. 7). It is also to be noted that the outer end of each of the lugs 49 is disposed inwardly with respect to the outermost edges of the castings. These faces of the web l t are completely imbedded in a heat resisting compound, such as a pliable chrome ore refractory, that is applied in a plastic state and rammed in place so as to completely fill the pockets formed by the depressed faces of the web M. This is illustrated best in Fig. 4, the Jlastic compound being shown at 53. This com pound 53 is supported on the shoulders Q1 and ii; of the sealing edge 46 (see Fig. 4) and completely covers the faces of the web 4 and imbeds the lugs 49. This compound has the property of taking an initial set on exposure to air and 01" hardening to a substantial degree upon exposure to high temperatures. When properly hardened the material becomes very hard and has the property of withstanding extremely high temperatures without deteriorating. Thus an effective protective coating is applied to the units or castings 12 that protects both the inner and outer faces thereof.

The heat resisting compound is also applied to the spaces 52 between the adjacent sealing Each of the sealing units A? may have its inner ends bevelled as shown at 55 so that the castings may either be arranged side by side or may be used as corner castings disposed at with respect to each other. In either event the heat resisting compound completely fills the spaces between the castings.

As shown in Fig. 3 the walls 22 of the soaking pit are each provided with a trough 56 that completely encircles the opening into the soaking pit chamber 2|. This trough 55 is disposed directly below the annular seal member 33 and is filled with a quantity of sand El into which the seal castings 42 are partially imbedded when the pit cover is in place. In this manner an effective seal is provided so as to eliminate as much as possible the escape of hot gases from the soaking pit chamber 2!.

As shown in Fig. 9 it may be desirable to extend the heat resisting compound protective coating above the sealing units 42 so as to protect additional portions of the structure. This may be accomplished by securing a plurality of web members 58 to the I-beams 3! or 32 as the case may be by means of welding or the like indicated at its and to each of these web members 58 is secured an angle plate Ell that is provided with ears 6| that are adapted to receive bolts 62 that pass through the ears and the webs Each angle plate 64 extends the full distance b tween adjacent web members 53 (see Fig. 1%- Projecting outwardly from the outer face of each of the angle plates are a plurality of lugs 54 that are spaced throughout the length of the height of the plate. In this embodiment of the invention the heat resisting compound is ap plied to a much greater depth on each of the sealing units 42 and is brought out to a position slightly beyond the outer plane of the lugs This compound is spread over the entire face of the angle plates and fills the spaces betweer adjacent angle plates 64 as illustrated in Fig. it. Thus a protective coating is applied to the side and end walls of the cover to a position well up along the I-bearos 3i and 32.

Still another embodiment of the invention illustrated in Fig. 11. In this form of the invention no channel member corresponding to member 49 in Fig. 4 is provided. Instead each of the sealing units 42 is provided with a taller web portion 44 so that the unit 52 in this instance is applied directly to the lower flange of each of the I-beam members 31 or 32 as the case may be. The heat resisting compound is applied to both inner and outer faces of the sealing units 42 previously described, but in this instance the protective coating thus formed extends to a position just below I-beam 32.

Thus there is provided a sealing ring that completely covers the lower peripheral margin of the soaking pit cover 3t. This ring is able to with-- stand extremely high temperatures and the cor rosive effect of the hot gases that normally escape from a soaking pit of the type described. The life of the sealing units or castings 42 is thereby greatly increased. To replace a casting 42 it is merely necessary to fracture the heat resisting compound protective coating so as to make it possible to remove the faulty casting and replace it with a new casting. A new coating of heat resisting compound is then applied to this new casting and after proper seasoning of this material the cover is again ready for use.

I claim:

1. A soaking pit cover including a tapered seal portion projecting downwardly along the pe riphery of the cover, said seal portion comprising a plurality of seal units arranged substantially end to end and secured to the cover, each unit being tapered downwardly to a relatively narrow edge, a plurality of lugs projecting from the faces of the unit, and a protective covering held on each face by the lugs and adapted to withstand high temperatures.

2. A soaking pit cover including a tapered seal portion projecting downwardly along the periphery of the cover, said seal portion comprising a plurality of seal units arranged substantially end to end and secured to the cover, each unit comprising an upper, substantially horizontal flange, a downwardly projecting web, the lower edge of the web providing a sealing edge, the sealing edge providing a shoulder along its edge facing the flange, and material at least partially supported on the shoulder and covering the faces of the web and adapted to withstand high temperatures.

3. A soaking pit cover including a tapered seal portion projecting downwardly along the periphery of the cover, said seal portion comprising a plurality of seal units arranged substantially end to end and secured to the cover, each unit comprising a downwardly projecting web having disposed at its lower edge a sealing edge, a plurality of lugs projecting from at least one face of the web, a shoulder provided at the lower end of the web and disposed on the same side of the web as the lugs, and material supported on the shoul der and by the lugs and covering the adjacent face of the web, said material being adapted to withstand high temperatures.

4. A soaking pit cover sealing unit comprising a metallic web portion having a tapered lower edge extending the length of the unit and forming a relatively narrow sealing edge, a shoulder provided adjacent to the sealing edge on each side of the web and extending the length of the unit, a plurality of lugs projecting from the faces of the unit, and a protective covering held on each face by the lugs and the adjacent shoulder and adapted to withstand high temperatures.

5. A soaking pit cover sealing unit comprising a metallic web portion having a tapered lower edge extending the length of the unit and forming a relatively narrow sealing edge, a shoulder provided adjacent to the sealing edge on each side of the web and extending the length of the unit, a plurality of outwardly projecting members on the faces of the unit, and lugs projecting from the faces of the unit, and a protective covering held on each face by the lugs and the adjacent shoulder and adapted to withstand high temperatures.

6. A soaking pit cover including a tapered seal portion projecting downwardly along the periphery of the cover, said seal portion comprising a plurality of seal units arranged substantially end to end and secured to the cover, each unit being tapered downwardly to a relatively narrow edge, a plurality of outwardly projecting members on the faces of the unit and lugs projecting from the faces of the unit, and a protective covering held on each face by the lugs and adapted to withstand high temperatures.

ROBERT W. HIGGINS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 184,473 Laughlin Nov. 21, 1876 569,485 Berg Oct. 13, 1896 1,029,319 Robinson June 11, 1912 1,691,369 Baker Nov. 13, 1928 2,124,888 Morton July 26, 1938 2,444,736 Hazen July 6, 1948. 

